stopwatch.java

简单的多字符java动画,方便理解Multi-threaded 的概念.

import java.util.*;

public class StopWatch
{
    Calendar startCal, endCal;

    String tzID = TimeZone.getDefault().getID();

    TimeZone tz = TimeZone.getTimeZone(tzID);

    /** Creates a new instance of StopWatch */
    public StopWatch()
    {
    }

    public StopWatch(String tzoneStr)
    {
        tz = TimeZone.getTimeZone(tzoneStr);
    }

    // Start the stopwatch
    public void start()
    {
        startCal = Calendar.getInstance(tz);
    }

    // Stop the stopwatch
    public void end()
    {
        endCal = Calendar.getInstance(tz);
    }

    // Measure the elapsed time in different units
    public double elapsedSeconds()
    {
        return (endCal.getTimeInMillis() - startCal.getTimeInMillis()) / 1000.0;
    }

    public long elapsedMillis()
    {
        return endCal.getTimeInMillis() - startCal.getTimeInMillis();
    }

    public double elapsedMinutes()
    {
        return (endCal.getTimeInMillis() - startCal.getTimeInMillis())
                / (1000.0 * 60.0);
    }

    public static void main(String[] args)
    {

        StopWatch sw = new StopWatch();
        sw.start(); // capture start time

        try
        {
            Thread.sleep(500); // sleep for 5 seconds
        } catch (Exception e)
        {
            System.out.println(e);
            System.exit(1);
        }

        sw.end(); // capture end time

        System.out.println("Elapsed time in minutes: " + sw.elapsedMinutes());
        System.out.println("Elapsed time in seconds: " + sw.elapsedSeconds());
        System.out.println("Elapsed time in milliseconds: "
                + sw.elapsedMillis());

        try
        {
            Thread.sleep(300); // sleep for 5 seconds
        } catch (Exception e)
        {
            System.out.println(e);
            System.exit(1);
        }

        sw.end(); // capture end time

        System.out.println("Elapsed time in minutes: " + sw.elapsedMinutes());
        System.out.println("Elapsed time in seconds: " + sw.elapsedSeconds());
        System.out.println("Elapsed time in milliseconds: "
                + sw.elapsedMillis());
    }
} // end of StopWatch class